SLA_DAV2M - Rotation Matrix from Axial Vector   

ACTION:

Form the rotation matrix corresponding to a given axial vector (double precision).

CALL:

CALL sla_DAV2M (AXVEC, RMAT)

GIVEN:

AXVEC axial vector (radians)

RETURNED:

RMAT rotation matrix

NOTES:

1.

A rotation matrix describes a rotation about some arbitrary axis. The axis is called the Euler axis, and the angle through which the reference frame rotates is called the Euler angle. The axial vector supplied to this routine has the same direction as the Euler axis, and its magnitude is the Euler angle in radians.

2.

If AXVEC is null, the unit matrix is returned.

3.

The reference frame rotates clockwise as seen looking along the axial vector from the origin.